Spark-plug



ci `1 'i fr yn@ ce alle .den

HARRY B. RUMMELL, OF FINDLAY, OHIO.

SEARK-PLUG.

meinen,

Specification of Letters atent.,

Application filed September 12, 1917. Serial No. 190,986.

To all whom t may concern.' f

Be it known the* l, HARRY B. RUMMELL, 'o citizen of the i tiled States, residing at Findlay, in the county of Hancock and State ot Ohio, have invented certain new and useful improvements in Spark-Plugs; and l do hereby declare. the following to lie a full, clear, and exact description ot the invention, such es will enable others skilled in the art to which it appertains to molte :ind use the sanie.

This; invention has for its oloject to prol vide un improved spark plug' for explosive engines, in which the center electrode is formed in two sections spaced an aoequate distance eport to provide an internal spark gap designed to increase the eliieiency ot' 'the plugy sind prevent short circuiting when the plug is fouled.

another object is the provision of ineens for rigidly anchoring the sections ci the center electrode in position in the insulator und also for maintaining them in predictormined spaced relation to each other.

iitli 'these and other objects in view, 'the ention consists in the novel construction, niliination and arrangement of parte as will he hereinafter specifically described,

'ined and lilluetrated in tlie accompanying drawing', i which:

lfginrc 1 represents e. side elevation o1"- the l g; 'oicd spari: plug,

s a longituoino'l sectional transverse sectional .ie line 3-3 et Fig. f5, oginentery trensv rowing; in detall. Where elerence numerals designate co.

Ing parts throughout the several the numeral 5 indice-tes theliody of ug which is provided et one end with l? Wrench jow-engaging feces and 1s duced and externally screw/threaded et its ipesite end, as indicated at '5, to facilitar-t "insertion in the spark plug port oit 'tn linder o' an engine (not shown). The oleo "cody, as usuel, is of hollow construetion end is provided with the internal here "7 which is restrictie( 'in 'its diameter et the shoulder 8.

reduced terminal 6, providiigen internal.,

'isuletor 9', constructed of porcelen,

'terminal of -tlie'section 1511s or other desired materiel, is inserted in the body 5 and pro]ects from the polygonal ternnnal thereof. The central portion of the,

'flic flange and the shoulder 8 to insure against leakage of the explosion vor products ot combustion.

rlhe relatively large-terminal of the plug body is formed with internal screivthreeds receiving' a ring' nut ll, which (3o-acts with the' flanged medial portion of the insulator il t0 rigidly anchor the latter in position in the plug body. A gasket is preferably inte posed between the nut and the llnange of the insulator to render the spark plug,` leali-proof.

The insulator' 10 is formed with o. longitudinal -bore 13, extending throughout its entire length, and. which 1s reduced at the end or" the insulator rdjacent the threaded terminal 6 ot the plug body, providing' the internal shoulder 1l, Twhich faces toward the n relatively large end of the 1cody The inner sectionv 15 of the center electrode is fitted within the relatively small terminal o the llore 13 and projects asliot distance Within the relatively large portie-nf thereof. The inner terminal ol" the section 15 is formed willi :in anchoring flange "i6 of circular lor-nlation and which Yis firmly seated. e@ 'ist the internal shonlder le foi-ined on VWell of the ooi-se The extreme inner ointed, es indicated at 17, and is disposed in spaced reletion to the adjacentpointed terminal 18 ot the outer center electrode section 19, which latter accommodated Within the relatively la" e portion or the door i3 and is provided Xvlb L u shoul '20. mlie reduc-ed terminal of the outer electrode section 19, and 'die adjacent terminal ofi the section 15, are received Within seperate tubular insulator 2G, constituting' .e spacing element for maintaining the electrodes in predeterminen spaced relation topi-event 'variance in the length of the spark ,cup 2l liet-Ween the electrode sections, The tuliuler insulator 2G is formed sepa" rately 1from the main insulator 9, and is inserted in the relatively large-terminal of the here 13, so es to facilitate rei'novel ozvtlie electrode' sections :from the porcelain liody, when desired. v Y

The end of the sectionll oppositeie Palmieri nel). ii, ieee.,

o reduced in er terminal defining esection 15 is externally screwthreaded, as indicated at 22, and is fitted Within an internally threaded recess formed in the hollow shank 23 of an anchoring cap 24, the apron or fia-nge of which latter is of frusto-eonical formation and is firmly engaged With the correspondingly formed terminal 25 of the insulator 9, so as to iirmly anchor the' cap 24 in position thereon. 4A nut 26 for securing the Wire, or other conductor, to the center electrode is tted upon the externally screwthreaded shank 23' and the outer electrode 27 of the spark plug is rigidly 'and electrically connected with the reduced termina] (5 or' the body 5, and is disposed in spaced ielation to the adjacent terminal of the inner center electrode section 15.

What I claim is:

A spark plug including a. hollow body, an insulator mounted therein and provided with an axial bore enlarged at one end to provide an inner annular shoulder, an electrode section fitted in the relatively small portion of said bore andl projecting into the relatively large portion thereof, said elecrelatively large portion of the bore trode section being provided with an outer annular shoulder spaced from its upper end and engaging the shoulder at the inner end of the enlarged portion of the 'bore so as to secure said section against downward movement, an outer electrode section fitted in the and provided at its inner end With'a reduced terminal member disposed in alinement with the upper end of the first mentioned electrode section' and spaced therefrom, and a tubular insulating member fitting snugly in the enlarged portion of the bore of said insulator and engaging the shoulder ofthe first mentioned electrode section and the lower end of the 'body portion of the electrode section mounted in theenlarged portion of the bore s0 as to maintain the tivo electrode sections in predetermined spaced relation.

In testimony whereof I affix my signature in presence of two Witnesses.

v HARRY B. RUMMELL. Witnesses:

MARY LAURE,

RALPH R. MILLER. 

